Topic 4.1: Properties of materials Flashcards
physical properties of materials
measurable properties that describes the state of materials, e.g. weight, mass, volume, density. can be identified through non destructive testing
Mass
relates to the amount of matter that is contained in a specific material. measured in kg (different from weight)
weight
a measure of force, unit: newtons
volume
the quantity of 3 dimensional space enclosed by a boundary
density
mass per unit volume of material
electrical resistivity
the measure of a material’s ability to conduct electricity. low resistivity = a good electrical conductor
Thermal conductivity
the measure of how fast heat is conducted through a slab of material with a given temperature difference across the slab
thermal expansion
- the measure of the degree of increase in dimensions when an object/material is heated.
- increases in volume, area, or length.
- expansivity is measured in fractional increase in dimensions per kelvin increase in temperature
hardness
resistance of a material to scratching or penetration
Mechanical properties
involvesthe relationship between stress and strain or a reaction to an applied force
measure through some form of destructive testing
* Tensile strength
* compressive strength
* Stiffness
* toughness
* ductility
* elasticity
* plasticity
material selection chart
chart used to select appropiate material based on desired properties
smart materials
have been designed to have 1 or + properties that can be modified when subject to an external stimuli in a way that the output can be controlled (they are reactive)
piezoelectricity
ability to release an electric charge when deformed
shape memory
pseudo-elastic property that allows their body to return to its original shape after deforming
photochromicity
ability to change color when exposed to light
